Allow to easily clean database

I agree...Nonetheless, you should have an option to sign that some specific tables should not be cleaned.

Following up on Diogo's, my suggested approach would be the wizard style screen with all the entities (and respective constraints reflection per colour coding) where you could tick the ones you wanted or ALL.

The new DbCleaner API was designed for this purpose. Check the documentation to understand the required privileges when using it.
As a lot of you mentioned, this is a very sensitive operation that we must ensure is only performed by the right person and under the right conditions.

This component at the Forge shows a small example of how to use the API. You can use it to adapt to your own security restrictions and policies.